Piston for internal-combustion engines.



G. R. RICH.

PISTON FOR INTERNAL COMBUSTION ENGINES.

APPLICATION map JULY no. me.

1,228,049 Pathtd May 29, 1917 v Hi llllllll os j GEORGE R. RICH, or enlcaoo, rumors.

PISTON FOR IlilTERNAfs-COMBUSTION ENGINES.

Specification of Letters Patent.

ran-moo Ma 29, 1m *1.

application filed July 10, 1916. Serial No. 108,309.

die it known that l, (ii-zones It. R1cn, a citizen oi the l'nitcd States, and a resident I p of Oak Park. county of Coolgand State of Illinois, have in ventedcertain new and useful Improvements m Pistons, for Internal- Combustion Engines, oi which the following -lower side of the piston head 111ay,he insu- 'ence of the heat developed fromthe eX- isvdeclared to be a full, clear, and exacfldescription.

ternalcombustion engines, and its primary ob ect is to provide a'plst'on wherein the lated thermotically from the intense heat developed at the top of the piston head. It,

is well known to those skilled in the art to which this invention pertains, that the piston head becomes very hot under the influplosions of the cmnhustible mixtures used in internal engines and that thelulnacatmg ml ,coming' in contact with the under side of to provide the piston head is often tried on the underside. thereof, whereby its efficiency as a lubricant is destroyed. It has been proposed a hollow space in the piston head to avoid this difiiculty, but from my experiments along this line, I have discovered that such a hollow space,.unprovided with other heat conducting means, causes the top of ,the piston head to become so duce premature explosions. With the present invention the lower face of the piston head is kept comparatively cool and the intense heat at the top of the head is conducted away therefrom and radiated or absorbed by the water-cooled cylinder walls. The invention consists therefore in a piston :having a hollow space in its piston head,

accompanying drawing, in which paralleling the head as well as the piston wall behind the piston rings; furthermore it consists in a piston having a hollow piston head formed with fins cast on the underside of the top of the piston head and extending to the piston wall. T heinvention furtherconsists in the several novel features hereinafter described and claimed: p

The invention is clearly illustrated in the :Figure 1, is a central, .longitudi jal section througha piston embodying one form of the present invention; Fig. an a horizontal section taken on the line 2-2 OfEIg. 1; Fig. 3,

line33 of Fig. .1, and Fig; 4, is a detail nor of the piston.

This invention relates to pistons for in-f as shown at '15.

1 ness of either top hot as .to prov fins are spaced away is a horizontal section taken on the fragmentai section taken at the upper cor- Referring to said drawii'ig, 1i), designates the annular piston wall of the piston. and 11, its head, which in the present instance is illustrated as cast integral with the wall 10, although it is not necessary to cast it into gral therewith.-

In accordance with the usual pttictice, the wrist pin bearingbosses-12, are cast on the inner face of the piston wall l0,and the ring receiving grooves are' formed in the externalface of the wall 10, for the ma ti-on of the piston rings 13. The piston head 11, is formed with a cavity or hollow space 7 14, which extends crosswise of the piston, and. at the annular wall of the piston said cavity is continued down behind the piston rings 13, in the form of an annular recess The top portion 16, of the head, and bottom portion 17, thereof may he parallel with each other if desired, and the hollow space may be wider than the thick- 16, or bottom portion 17. To form the annular portion 15, of the cavity, the bottom portion 17, of the head formed with a down turned annular wall 18. the lower edge of which. is turned outward as at 19, and joins with the annular piston wall 10. The cavity is conveniently formed by casting the piston with a core in the head, and a hollow boss 20,0pens out from the cavity through which the core may-be removed; said boss 2Q, is internally threaded and a threaded plug 21, is screwed into the boss to hermetically seal the cavity. i I

Preferably the air is exhausted from the cavity before the plug is screwed in so as to into the same at the center; the fins are increased in height near the annular wall and their lower edges merge thereinto. Said from the bottom portion 17, to guard against heat being conducted to said bottom portion; said fins are cast webs 22, upon integralwith the top portion and act td con- 9 duct much of the intense heat to the annular wall 10,.of the piston, from which it is absorbed byfthe water-cooled cylinder Wall of the engine. Furthermore the bottom por tion 17,.will he kept comparatively cool because of the cavity between it and the top motici'insulator is increased By reason of thej cooled. .bottoni portion 17, the lubricating'oilhsplashing against said bottom portion'is riotjsubject' to the deleterious eEect of a hotfpiston head.

' down from the underside of the top portion More "or less variation 'ofthe exact de- Sdld wall outside of said annular recess.

tails of construction is possible Without departingfrom the spirit of this invention; Ifdesire, therefore; not to limit myself to the exact details of construction shown and described, but intend in the following claims to pointout all of the invention disclosed herein.

I claim as new and desire to secure by Letters Patent:

1. A piston for internal combustion en- --gin es, having a, hollow piston head, the hollow space, being completely inclosed and there beingfins in the hollow space, formed on the underside of the top portion and extending to the annular wall portion of the '2. A cast metal piston for internal comhollow head.

bustion engines, having a hollow piston head cast with radiallyextending fins in the hollow portion, the hollow space being completely inclosed and said fins extending I 0mm; hollow head and their lower edges merging into said top portion and into the annular wall of tht pistonv head.

'40 3. A piston tor internal combustion enmzaoae 7 gines, having an annular wall open atthe bottom and a hollow piston head, thehollow space being completely inclosed and the head being formed with heat conducting fins-on the top portion of the hollow head, said fins being located in the hollow space. 1

LA piston for internal combustion en-' gines, having" a head formed with an isolatedcavity extending to the annular wall of the piston and then down along the inside thereof in the form of an annular recess, there being one or more annular ring receiving grooves in the external face of annular piston wall in the form of an annu lar space, and there being'raclially extending heat. conducting fins formed on the underside ofthe top portion of said hollow head and extending to the annular wall of the head.

6. A piston for internal combustion engines, cast with a hollow piston head having a partial vacuum therein.

7. A piston for internal combustionen'- gines, having a vacuum chamber in its head.

8. A piston for internal combustion engines, having an isolated hollow space in its head formed by an integral wall paralleling the face of the head and a portion of the annular wall, said piston having piston ring receiving grooves formed in the external face of said *wall outside of said hollow 

